The present invention is directed to an hydraulic antivibration device. More specifically, the present invention is directed to an improved flow channel deflector for a hydraulic engine mount.
A typical engine mount contains two sealed chambers separated by an intermediate partition having a damping channel passing there through and providing communication between the chambers. The engine mount normally has one end member attached to an engine block and another end member attached to a vehicle frame, with the end members being resiliently connected to each other by an elastomeric member which permits one end member to move in response to vibrations with respect to the other. In order to damp vibrations between the two end members, hydraulic fluid is pumped back and forth from one chamber to the other through the damping channel in the partition.
The damping channel may be formed in a variety of methods. The most conventional method is with the use of a pair of thick metal plates. Within each metal plate, a partial arcuate groove is formed around the circumference of each plate and then the plates are matched so that the grooves are aligned, forming a channel. The channel opening and exit are offset from each other so that the fluid must flow at least partially through the channel to get from one chamber to the other.
These conventional plates are formed by casting, press forming or machining thick metal into which the grooves are machined.
The present invention is directed to a simplified construction of the damper plate resulting in a lighter weight damper plate and easier construction of the mount.
The present invention is a hydraulically damped anti-vibration mount. The mount has a rubber spring, an outer metal casing, an end cap, and a damper plate. The spring is encased within the outer metal casing, the outer metal casing being crimped to the end cap, and the damper plate dividing the interior of the mount into an upper and a lower chamber. The damper plate is formed from an upper plate and a lower plate. The upper and lower plates form a flow channel between the two plates which extends at least partially around the circumference of the damper plate, the flow channel permitting communication between the upper and lower chamber. The upper plate has an opening communicating to the upper chamber with an integral tab extending from the opening into the flow channel to block the channel.
In one aspect of the invention, the upper plate is a flat metal plate to form the top of the flow channel. The lower plate has a trough extending about the circumference of the plate to form the base of the flow channel.
The tab formed in the top plate may be generally L-shaped, extending both into the flow channel and along the flow channel. The tab may be fixedly secured to the base of the flow channel.